Project ForgeProcess Calculations
Laws of Thermodynamics
GATE 2013
Medium
An equation of state is explicit in pressure p and cubic in the specific volume v. At the critical point 'c', the isotherm passing through 'c' satisfies
- A(∂p/∂v)<0, (∂²p/∂v²)=0
- B(∂p/∂v)>0, (∂²p/∂v²)<0
- C(∂p/∂v)=0, (∂²p/∂v²)>0
- (∂p/∂v)=0, (∂²p/∂v²)=0
Explanation
At the critical point on a p-v isotherm, the curve has a horizontal inflection point: both the first and second derivatives of p with respect to v vanish, i.e. (∂p/∂v)_T=0 and (∂²p/∂v²)_T=0.
Source: GATE CH 2013 (2013)
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